Detecting location within a network

ABSTRACT

Systems and methods for detecting the presence of a body in a network without fiducial elements, using signal absorption, and signal forward and reflected backscatter of radio frequency (RF) waves caused by the presence of a biological mass in a communications network.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Utility patentapplication Ser. No. 15/600,380, filed May 19, 2017, which is acontinuation of U.S. Utility patent application Ser. No. 15/227,717,filed Aug. 3, 2016, and issued on Jun. 27, 2017, as U.S. Utility Pat.No. 9,693,195, which claims the benefit of U.S. Provisional PatentApplication No. 62/252,954, filed Nov. 9, 2015, and U.S. ProvisionalPatent Application No. 62/219,457, filed Sep. 16, 2015 and which is acontinuation of U.S. Utility patent application Ser. No. 15/084,002,filed Mar. 29, 2016, and issued on Oct. 18, 2016, as U.S. Utility Pat.No. 9,474,042, which applications in turn also claim benefit of theabove-referenced provisional applications. The entire disclosure of allof these documents is herein incorporated by reference.

BACKGROUND 1. Field of the Invention

This disclosure is related to the field of object detection, and moreparticularly to systems and methods for detecting the presence of abiological mass within a wireless communications network.

2. Description of the Related Art

Tracking objects may be done using a number of techniques. For example,a moving transceiver may be attached to the object. Examples of suchsystems include global positioning location systems such as GPS, whichuse orbiting satellites to communicate with terrestrial transceivers.However, such systems are generally less effective indoors, wheresatellite signals may be blocked, reducing accuracy. Thus, othertechnologies are often used indoors, such as Bluetooth™ beacons, whichcalculate the location of a roaming or unknown transceiver. The roamingtransceiver acts as a fiducial element.

These systems have several disadvantages, among them that the objecttracked must include a transceiver. In certain applications, the objectto be tracked will have no such fiducial element, or will activelydisable any such element, such as an intruder in a home.

Other technologies exist which can also detect and track objects withoutthe use of a fiducial element. For example, radar is a venerableobject-detection system that uses RF waves to determine the range,angle, or velocity of objects, including aircraft, ships, spacecraft,guided missiles, motor vehicles, weather formations, and terrain. Radaroperates by transmitting electromagnetic waves, generally using waves inthe radio frequency (“RF”) of the electromagnetic spectrum, whichreflect from any object in their path. A receiver, typically part of thesame system as the transmitter, receives and processes these reflectedwaves to determine properties of the objects. Other systems similar toradar, using other parts of the electromagnetic spectrum, may also beused in similar fashion, such as ultraviolet, visible, or near-infraredlight from lasers.

Radar technologies do not require a fiducial element, but have othershortcomings. For example, radar signals are susceptible to signalnoise, or random variations in the signal caused by internal electricalcomponents, as well as noise and interference from external sources,such as the natural background radiation. Radar is also vulnerable toexternal interference sources, such as intervening objects blocking thebeam path and can be deceived by objects of particular size, shape, andorientation.

SUMMARY

The following is a summary of the invention in order to provide a basicunderstanding of some aspects of the invention. This summary is notintended to identify key or critical elements of the invention or todelineate the scope of the invention. The sole purpose of this sectionis to present some concepts of the invention in a simplified form as aprelude to the more detailed description that is presented later.

Because of these and other problems in the art, there is describedherein, among other things, is a method for detecting the presence of ahuman comprising: providing a first transceiver disposed at a firstposition within a detection area; providing a second transceiverdisposed at a second location within the detection area; a computerserver communicably coupled to the first transceiver; the firsttransceiver receiving a first set of wireless signals from the secondtransceiver via the wireless communications network; the computer serverreceiving a first set of signal data from the first transceiver, thefirst set of signal data comprising data about the properties of thefirst set of wireless signals, the property data being generated as partof ordinary operation of the first transceiver on the communicationnetwork; the computer server creating a baseline signal profile forcommunications from the second transceiver to the first transceiver, thebaseline signal profile being based at least in part on the wirelesssignal properties in the received first set of signal data, andrepresenting characteristics of wireless transmissions from the secondtransceiver to the first transceiver when no human is present in thedetection area; the first transceiver receiving a second set of wirelesssignals from the second transceiver via the wireless communicationsnetwork; the computer server receiving a second set of signal data fromthe first transceiver, the second set of signal data comprising dataabout the properties of the second set of wireless signals, the propertydata being generated as part of ordinary operation of the firsttransceiver on the communication network; and the computer serverdetermining whether a human is present within the detection area, thedetermination based at least in part on a comparison of the wirelesssignal properties in the received second set of wireless signal data tothe baseline signal profile.

In an embodiment of the method, the first set of signal propertiescomprise wireless network signal protocol properties determined by thefirst transceiver.

In another embodiment of the method, the wireless network signalprotocol properties are selected from the group consisting of: receivedsignal strength, latency, and bit error rate.

In another embodiment of the method, the method further comprises:providing a third transceiver disposed at a third location within thedetection area; the first transceiver receiving a third set of wirelesssignals from the third transceiver via the wireless communicationsnetwork; the computer server receiving a third set of signal data fromthe first transceiver, the third set of signal data comprising dataabout the properties of the third set of wireless signals, the propertydata being generated as part of ordinary operation of the firsttransceiver on the communication network; the computer server creating asecond baseline signal profile for communications from the thirdtransceiver to the first transceiver, the second baseline signal profilebeing based at least in part on the wireless signal properties in thereceived third set of signal data, and representing characteristics ofwireless transmissions from the third transceiver to the firsttransceiver when no human is present in the detection area; the firsttransceiver receiving a fourth set of wireless signals from the thirdtransceiver via the wireless communications network; the computer serverreceiving a fourth set of signal data from the first transceiver, thefourth set of signal data comprising data about the properties of thefourth set of wireless signals, the property data being generated aspart of ordinary operation of the first transceiver on the communicationnetwork; and in the determining step, the computer server determiningwhether a human is present within the detection area based at least inpart on a comparison of the wireless signal properties in the receivedfourth set of wireless signal data to the second baseline signalprofile.

In another embodiment of the method, the determining step appliesstatistical methods to the second set of wireless signal data todetermine the presence of a human.

In another embodiment of the method, the method further comprises: thecomputer server continuously determining the presence or absence of ahuman within the detection area, the determination based at least inpart on a comparison of the baseline signal profile to signal datacomprising data about the properties of the first set of wirelesssignals received continuously at the computer server from the firsttransceiver; and the computer continuously updating the baseline signalprofile based on the continuously received signal data when thecontinuously received signal data indicates the absence of a human inthe detection area.

In another embodiment of the method, the method further comprises: thecomputer server determining the number of humans is present within thedetection area, the determination based at least in part on a comparisonof the received second set of signal properties to the baseline signalprofile.

In another embodiment of the method, the method further comprises: thecomputer server determining the location of one or more humans withinthe detection area, the determination based at least in part on acomparison of the received second set of signal properties to thebaseline signal profile.

In another embodiment of the method, the method further comprises: thecomputer server being operatively coupled to a second system; and onlyafter the computer server detects the presence of a human in thedetection area, the computer operates the second system.

In another embodiment of the method, the detection network and thesecond system are configured to communicate using the same communicationprotocol.

In another embodiment of the method, the second system is an electricalsystem.

In another embodiment of the method, the second system is a lightingsystem.

In another embodiment of the method, the second system is a heating,venting, and cooling (HVAC) system.

In another embodiment of the method, the second system is a securitysystem.

In another embodiment of the method, the second system is an industrialautomation system.

In another embodiment of the method, the wireless communication protocolis selected from the group consisting of: Bluetooth™, Bluetooth™ LowEnergy, ANT, ANT+, WiFi, Zigbee, Thread, and Z-Wave.

In another embodiment of the method, the wireless communication networkhas a carrier frequency in the range of 850 MHz and 17.5 GHz inclusive.

In another embodiment of the method, the determination whether a humanis present within the detection area is adjusted based on machinelearning comprising: determining a first sample location of a humanhaving a fiducial element in the detection area, the first samplelocation being determined based upon detecting the fiducial element;determining a second sample location of the human in the detection area,the second sample location being determined based at least in part on acomparison of the received second set of signal data to the baselinesignal profile not utilizing the fiducial element; comparing the firstsample location and the second sample location; and adjusting thedetermination step based on non-fiducial element location to improve thelocation calculating capabilities of the system, the adjusting basedupon the comparing step.

In another embodiment of the method, the determination whether a humanis present within the detection area is adjusted based on machinelearning comprising: determining based on user input or action that ahuman was present in an area when the sample signal propertiescorrespond at least in part with baseline signal properties of an emptyspace, modifying, at least in part, the baseline signal properties foran empty space; modifying, at least in part, the signal propertiesassociated with an occupied space; and adjusting the method forcomparing sample signal properties to the baseline and other comparativesignal properties to improve the accuracy of the system over time.

In an embodiment of the system, the user input or action which providespresence data is provided directly to the system in some form including,but not limited to, physical switches, smartphone input, or auditorycues.

In an embodiment of the system, the user input or action which providespresence data is provided indirectly to the system in some form, such asdeliberately changing the signal profile to counteract a decision beingtaken by the system, such as providing such a change during a dimmingphase in a lighting system.

In another embodiment of the method, the method further comprises: thecomputer server storing a plurality of historical data recordsindicative of whether a human was present in the detection area over aperiod of time, each of the historical data records comprising anindication of the number of humans detected in the detected area and thedate and time of when the number of humans was detected in the detectionarea; and the computer server making the historical data recordsavailable to one or more external computer systems via an interface.

Also described herein, among other things, is a method for detecting thepresence of a human comprising: providing a first transceiver disposedat a first position within a detection area; providing a secondtransceiver disposed at a second location within the detection area;providing a computer server communicably coupled to the firsttransceiver; providing a first external system operatively coupled tothe computer server; providing a second external system operativelycoupled to the computer server; the computer server receiving from thefirst transceiver a set of baseline signal data comprising property dataabout the signal properties of a first set of wireless signals receivedby the first transceiver from the second transceiver when no human ispresent in the detection area, the property data being generated by thefirst transceiver as part of ordinary operation of the first transceiveron the communication network; the computer server creating a baselinesignal profile for communications from the second transceiver to thefirst transceiver when no human is present in the detection area, thebaseline signal profile being based at least in part on the propertydata representing characteristics of wireless transmissions from thesecond transceiver to the first transceiver when no human is present inthe detection area; the computer server receiving from the firsttransceiver a first set of sample baseline signal data comprisingproperty data about the signal properties of a second set of wirelesssignals received by the first transceiver from the second transceiverwhen a human is present in the detection area, the property data beinggenerated by the first transceiver as part of ordinary operation of thefirst transceiver on the communication network; the computer servercreating a first sample baseline signal profile for communications fromthe second transceiver to the first transceiver when a human is presentin the detection area, the first sample baseline signal profile beingbased at least in part on the property data in the first set of samplebaseline signal data, representing characteristics of wirelesstransmissions from the second transceiver to the first transceiver whena human is present in the detection area; the computer server receivingfrom the first transceiver a second set of sample baseline signal datacomprising property data about the signal properties of a third set ofwireless signals received by the first transceiver from the secondtransceiver when a human is present in the detection area, the propertydata being generated by the first transceiver as part of ordinaryoperation of the first transceiver on the communication network; thecomputer server creating a second sample baseline signal profile forcommunications from the second transceiver to the first transceiver whena human is present in the detection area, the second sample baselinesignal profile being based at least in part on the property data in thesecond set of sample baseline signal data, representing characteristicsof wireless transmissions from the second transceiver to the firsttransceiver when a human is present in the detection area; the computerserver receiving from the first transceiver a third set of samplebaseline signal data comprising property data about the signalproperties of a fourth set of wireless signals received by the firsttransceiver from the second transceiver when a human is present in thedetection area, the property data being generated by the firsttransceiver as part of ordinary operation of the first transceiver onthe communication network; the computer server determining to operatethe first external system based upon the computer server determiningthat the property data in the third set of sample baseline signal datacorresponds to the first sample baseline signal profile; the computerserver determining not to operate the second external system based uponthe computer server determining that the property data in the third setof sample baseline signal data does not correspond to the second samplebaseline signal profile.

In an embodiment of the method, the determination to operate the firstexternal system and the determination not to operate the second externalsystem is adjusted based on machine learning comprising: determining afirst sample location of a human having a fiducial element in thedetection area, the first sample location being determined based upondetecting the fiducial element; determining a second sample location ofthe human in the detection area, the second sample location beingdetermined based at least in part on a comparison of the received secondset of signal data to the baseline signal profile not utilizing thefiducial element; comparing the first sample location and the secondsample location; and adjusting the determination steps based onnon-fiducial element location to improve the location calculatingcapabilities of the system, the adjusting based upon the comparing step.

In another embodiment of the method, the determination to operate thefirst external system and the determination not to operate the secondexternal system is adjusted based on machine learning comprising:determining a first sample location of a human in the detection areausing inference, the first sample location being determined based upondetecting the human interacting with the system in some known way;determining a second sample location of the human in the detection area,the second sample location being determined based at least in part on acomparison of the received second set of signal data to the baselinesignal profile not utilizing the inferred location; comparing the firstsample location and the second sample location; and adjusting thedetermination steps based on inferred location to improve the locationcalculating capabilities of the system, the adjusting based upon thecomparing step.

In another embodiment of the method, the property data about thewireless signals comprises data about signal properties selected fromthe group consisting of: received signal strength, latency, and biterror rate.

In another embodiment of the method, the computer server creates thefirst sample baseline signal profile by applying statistical methods tothe first set of sample baseline signal data, and the computer servercreates the second sample baseline signal profile by applyingstatistical methods to the second set of sample baseline signal data.

In another embodiment of the method, the method further comprises: thecomputer server receiving from the first transceiver additional sets ofbaseline signal data comprising property data about the signalproperties of a second set of wireless signals received by the firsttransceiver from the second transceiver, the property data beinggenerated by the first transceiver as part of ordinary operation of thefirst transceiver on the communication network and the computer serverupdating the baseline signal profile based on the continuously receivedadditional sets of baseline signal data when the continuously receivedsets of baseline signal data indicate the absence of a human in thedetection area.

In another embodiment of the method, the method further comprises: thecomputer server receiving from the first transceiver a set of signaldata comprising property data about the signal properties of a secondset of wireless signals received by the first transceiver from thesecond transceiver when one or more humans are present in the detectionarea, the property data being generated by the first transceiver as partof ordinary operation of the first transceiver on the communicationnetwork; the computer server determining the quantity of humans presentin the detection area based at least in part on a comparison of the setof signal data to the baseline signal profile.

In another embodiment of the method, the method further comprises: thecomputer server determining a location of each of the one or more humanspresent in the detection area, the determination based at least in parton a comparison of the set of signal data to the baseline signalprofile.

In another embodiment of the method, when a human is present in thedetection area, the computer server determines that a human is presentin the detection area and operates the first external system even if theproperty data in the third set of sample baseline signal datacorresponds to the second sample baseline signal profile.

In another embodiment of the method, when a human is present in thedetection area, the computer server determines that a human is presentin the detection area and operates the second external system only ifthe property data in the third set of sample baseline signal datacorresponds to the second sample baseline signal profile.

In another embodiment of the method, the wireless communication networkhas a carrier frequency in the range of 850 MHz and 17.5 GHz inclusive.

In another embodiment of the method, the method further comprises: thecomputer server storing a plurality of historical data recordsindicative of whether a human was present in the detection area over aperiod of time, each of the historical data records comprising anindication of the number of humans detected in the detected area and thedate and time of when the number of humans was detected in the detectionarea; and the computer server making the historical data recordsavailable to one or more external computer systems via an interface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an embodiment of a system according tothe present disclosure.

FIG. 2 is a flow chart of an embodiment of a method according to thepresent disclosure.

FIG. 3A depicts a schematic diagram of a system for change detection ina detection network over time according to the present disclosure.

FIG. 3B depicts a schematic diagram of a system for detecting changes inlocations of humans in a detection network over time according to thepresent disclosure.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The following detailed description and disclosure illustrates by way ofexample and not by way of limitation. This description will clearlyenable one skilled in the art to make and use the disclosed systems andmethods, and describes several embodiments, adaptations, variations,alternatives and uses of the disclosed systems and methods. As variouschanges could be made in the above constructions without departing fromthe scope of the disclosures, it is intended that all matter containedin the description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

Generally speaking, described herein, among other things, are systemsand methods for detecting the presence of a body in a network withoutfiducial elements. Generally speaking, the systems and methods describedherein use signal absorption, and signal forward scatter and reflectedbackscatter of the RF communication caused by the presence of abiological mass in a communications network, generally a mesh network.

Throughout this disclosure, the term “computer” describes hardware whichgenerally implements functionality provided by digital computingtechnology, particularly computing functionality associated withmicroprocessors. The term “computer” is not intended to be limited toany specific type of computing device, but it is intended to beinclusive of all computational devices including, but not limited to:processing devices, microprocessors, personal computers, desktopcomputers, laptop computers, workstations, terminals, servers, clients,portable computers, handheld computers, smart phones, tablet computers,mobile devices, server farms, hardware appliances, minicomputers,mainframe computers, video game consoles, handheld video game products,and wearable computing devices including but not limited to eyewear,wrist-wear, pendants, and clip-on devices.

As used herein, a “computer” is necessarily an abstraction of thefunctionality provided by a single computer device outfitted with thehardware and accessories typical of computers in a particular role. Byway of example and not limitation, the term “computer” in reference to alaptop computer would be understood by one of ordinary skill in the artto include the functionality provided by pointer-based input devices,such as a mouse or track pad, whereas the term “computer” used inreference to an enterprise-class server would be understood by one ofordinary skill in the art to include the functionality provided byredundant systems, such as RAID drives and dual power supplies.

It is also well known to those of ordinary skill in the art that thefunctionality of a single computer may be distributed across a number ofindividual machines. This distribution may be functional, as wherespecific machines perform specific tasks; or, balanced, as where eachmachine is capable of performing most or all functions of any othermachine and is assigned tasks based on its available resources at apoint in time. Thus, the term “computer” as used herein, can refer to asingle, standalone, self-contained device or to a plurality of machinesworking together or independently, including without limitation: anetwork server farm, “cloud” computing system, software-as-a-service, orother distributed or collaborative computer networks.

Those of ordinary skill in the art also appreciate that some deviceswhich are not conventionally thought of as “computers” neverthelessexhibit the characteristics of a “computer” in certain contexts. Wheresuch a device is performing the functions of a “computer” as describedherein, the term “computer” includes such devices to that extent.Devices of this type include but are not limited to: network hardware,print servers, file servers, NAS and SAN, load balancers, and any otherhardware capable of interacting with the systems and methods describedherein in the matter of a conventional “computer.”

Throughout this disclosure, the term “software” refers to code objects,program logic, command structures, data structures and definitions,source code, executable and/or binary files, machine code, object code,compiled libraries, implementations, algorithms, libraries, or anyinstruction or set of instructions capable of being executed by acomputer processor, or capable of being converted into a form capable ofbeing executed by a computer processor, including without limitationvirtual processors, or by the use of run-time environments, virtualmachines, and/or interpreters. Those of ordinary skill in the artrecognize that software can be wired or embedded into hardware,including without limitation onto a microchip, and still be considered“software” within the meaning of this disclosure. For purposes of thisdisclosure, software includes without limitation: instructions stored orstorable in RAM, ROM, flash memory BIOS, CMOS, mother and daughter boardcircuitry, hardware controllers, USB controllers or hosts, peripheraldevices and controllers, video cards, audio controllers, network cards,Bluetooth™ and other wireless communication devices, virtual memory,storage devices and associated controllers, firmware, and devicedrivers. The systems and methods described here are contemplated to usecomputers and computer software typically stored in a computer- ormachine-readable storage medium or memory.

Throughout this disclosure, terms used herein to describe or referencemedia holding software, including without limitation terms such as“media,” “storage media,” and “memory,” may include or excludetransitory media such as signals and carrier waves.

Throughout this disclosure, the term “network” generally refers to avoice, data, or other telecommunications network over which computerscommunicate with each other. The term “server” generally refers to acomputer providing a service over a network, and a “client” generallyrefers to a computer accessing or using a service provided by a serverover a network. Those having ordinary skill in the art will appreciatethat the terms “server” and “client” may refer to hardware, software,and/or a combination of hardware and software, depending on context.Those having ordinary skill in the art will further appreciate that theterms “server” and “client” may refer to endpoints of a networkcommunication or network connection, including but not necessarilylimited to a network socket connection. Those having ordinary skill inthe art will further appreciate that a “server” may comprise a pluralityof software and/or hardware servers delivering a service or set ofservices. Those having ordinary skill in the art will further appreciatethat the term “host” may, in noun form, refer to an endpoint of anetwork communication or network (e.g., “a remote host”), or may, inverb form, refer to a server providing a service over a network (“hostsa website”), or an access point for a service over a network.

Throughout this disclosure, the term “real time” refers to softwareoperating within operational deadlines for a given event to commence orcomplete, or for a given module, software, or system to respond, andgenerally invokes that the response or performance time is, in ordinaryuser perception and considered the technological context, effectivelygenerally cotemporaneous with a reference event. Those of ordinary skillin the art understand that “real time” does not literally mean thesystem processes input and/or responds instantaneously, but rather thatthe system processes and/or responds rapidly enough that the processingor response time is within the general human perception of the passageof real time in the operational context of the program. Those ofordinary skill in the art understand that, where the operational contextis a graphical user interface, “real time” normally implies a responsetime of no more than one second of actual time, with milliseconds ormicroseconds being preferable. However, those of ordinary skill in theart also understand that, under other operational contexts, a systemoperating in “real time” may exhibit delays longer than one second,particularly where network operations are involved.

Throughout this disclosure, the term “transmitter” refers to equipment,or a set of equipment, having the hardware, circuitry, and/or softwareto generate and transmit electromagnetic waves carrying messages,signals, data, or other information. A transmitter may also comprise thecomponentry to receive electric signals containing such messages,signals, data, or other information, and convert them to suchelectromagnetic waves. The term “receiver” refers to equipment, or a setof equipment, having the hardware, circuitry, and/or software to receivesuch transmitted electromagnetic waves and convert them into signals,usually electrical, from which the message, signal, data, or otherinformation may be extracted. The term “transceiver” generally refers toa device or system that comprises both a transmitter and receiver, suchas, but not necessarily limited to, a two-way radio, or wirelessnetworking router or access point. For purposes of this disclosure, allthree terms should be understood as interchangeable unless otherwiseindicated; for example, the term “transmitter” should be understood toimply the presence of a receiver, and the term “receiver” should beunderstood to imply the presence of a transmitter.

Throughout this disclosure, the term “detection network” refers to awireless network used in the systems and methods of the presentdisclosure to detect the presence of biological mass interposed withinthe communications area of the network. A detection network may usegeneral networking protocols and standards and may be, but is notnecessarily, a special-purpose network. That is, while the nodes in thenetwork could be deployed for the specific purpose of setting up awireless detection network according to the present invention, they neednot be and generally will not be. Ordinary wireless networks establishedfor other purposes may be used to implement the systems and methodsdescribed herein. In the preferred embodiment, the detection networkuses a plurality of Bluetooth™ Low Energy nodes, but the presentdisclosure is not limited to such nodes. Each node acts as a computerwith an appropriate transmitter and receiver for communicating over thenetwork. Each of the computers provides a unique identifier within thenetwork whenever transmitting a message such that a receiving computeris capable of discerning from where the message originated. Such messageorigination information will usually be critical to the functioning ofthe invention as described in this detailed description. The receivingcomputer then analyzes the incoming signal properties, including but notlimited to, signal strength, bit error rate, and message delay. Thedetection network may be a mesh network, which means a network topologyin which each node relays data from the network.

Throughout this disclosure, the term “node” refers to a start point orendpoint for a network communication, generally a device having awireless transceiver and being a part of a detection network. Nodes aregenerally standalone, self-contained networking devices, such aswireless routers, wireless access points, short-range beacons, and soforth. A node may be a general-purpose device or a special-purposedevice configured for use in a detection network as described herein. Byway of example and not limitation, a node may be a device having thewireless transmission capabilities of an off-the-shelf wirelessnetworking device with the addition of specialized hardware, circuitry,componentry, or programming for implementing the systems and methodsdescribed herein; that is, for detecting significant changes to signalproperties, including but not limited to, signal strength, bit errorrate, and message delay. Within a detection network, each node can actas both a transmitter of signal to the network, as well as a receiverfor other nodes to push information. In the preferred embodiment, thenodes utilize Bluetooth™ Low Energy (BLE) as a wireless networkingsystem.

Throughout this disclosure, the term “continuous” refers to somethinghappening at an ongoing basis over time, whether such events aremathematically continuous or discontinuous. The generally acceptedmathematical definition of “continuous function” describes a functionwhich is without holes or jumps, generally described by two-sidedlimits. The technology described herein is based upon disturbances to atelecommunications system, in which the transceivers transmit atdiscrete intervals, and the received raw data is taken discretely, i.e.at discrete time intervals. The resulting data is itself may be discretein that it captures the characteristic of the system during a particularobservation window (i.e., the time interval). In a physical ormathematical sense, this mechanism is essentially a set of discrete datapoints in time, implying a discontinuous function. However, in thecontext of the technology, one of ordinary skill in the art wouldunderstand a system exhibiting this type of behavior to be “continuous”given that such measurements are taken at an ongoing basis over time.

The measurable energy density signature of RF signals is impacted byenvironmental absorbers and reflectors. Many biological masses, such ashumans, are mostly water and act as significant energy absorbers. Otherattributes of people such as clothing, jewelry, internal organs, etc.all further impact the measurable RF energy density. This isparticularly true where RF communication devices are transmitting overrelatively short distances (e.g., less than 50 meters), such asBluetooth™, WiFi™, 802.15.4 (Zigbee, Thread), and Z-Wave transceivers. Ahuman who passes through the physical space of the network will causesignal absorption and disruption. Due to relative uniformity in size,density, and mass composition, human bodies can cause characteristicsignal absorption, scattering, and measurable reflection. Changes insignal behavior and/or characteristics are generally referred to hereinas “Artifacts.” Such phenomena are particularly useful in theIndustrial, Scientific, and Medical (ISM) bands of the RF spectrum, butare generally observable in bands beyond these.

In an RF communication system comprising a transmitter and receiverseparated in space, signals received by the receiver from a giventransmitter are made up of energy from the original transmitted messagewhich has arrived at the receiver. Objects generally in the transmissionpath will affect the characteristics of ultimate signal which arrives atthe receiver.

Communication systems are generally designed to handle such issues andstill faithfully reproduce the message from the transmitter. Sincehumans generally exist, as far as RF communications are impacted, as amass of water, one such observable difference between human presence andabsence in a detection network is signal absorption by the human.Generally, the closer to the transmitter or receiver, the moresignificant the absorption is likely to be.

Generally, it is envisioned that humans will produce artifacts in adetection network in a somewhat predictable manner, which can bedetected or identified programmatically by detection algorithms.Further, artifacts may be cross correlated across the network todetermine an estimated position of the object causing the artifact. Theaccuracy of this estimation may vary with the algorithmschosen/constructed, and with the equipment used in the individualsystem.

For each given algorithm which is chosen/constructed, the system maybuild such detections as a combination of a baseline signal profile withno human present in the detection area and sample baseline signal datawith a human present in the detection area. New incoming sample baselinesignal data may be compared against both the known sample baselinesignal data and the baseline signal profile to determine the presence orabsence of humans in a space.

Short-range low power communication networks typically operate usingsignals in the 2.4 GHz frequency band, which is notable for beingwell-within the energy frequencies humans have been observed to absorb.As indicated, a human body physically interposed in a detection networkabsorbs and/or reflects at least some of the signals transmitted betweenand among nodes. However, other effects may also take place, such asforward and backward scattering. Utilizing the collection of data in adetection network without a human present to establish a baseline, andexamining future elements of said data for statistically significantdifferences typically exhibited by the physical presence of one or morehumans, whether or not the one or more humans is moving, the detectionnetwork makes the determination as to the presence or absence of humanswithin the network.

Depending on the communication network itself, hardware used, and thehuman, those changes may register within the network in different waysand produce different results; however, such changes are detectable.This differs from radar technologies in that detection of the objectdoes not necessarily rely or depend upon only signal reflection, butoften rather the opposite principle—signal absorption—which is detectedvia measurable changes in signal characteristics between a transmitterand receiver in different physical locations.

By analyzing the change in signal characteristics between nodes withinthe network, the position of a disruptor and—e.g., a human body—can becalculated relative to the network. Because the mere presence of thebody is sufficient, this system does not necessarily include a fiducialelement, and it need not rely on motion or movement. Because no fiducialelement is required, the systems and methods described herein mayprovide an anonymous location data reporting service, allowing for thecollection of data concerning traffic, travel routes, and occupancywithout requiring additional components or devices to be associated withthe bodies being tracked. Generally speaking, the systems and methodsdescribed herein operate in real time.

FIG. 1 is a schematic diagram of a system and method according to thepresent disclosure. In the depicted embodiment (101) of FIG. 1, adetection network (103) comprising a plurality of nodes (107) isdisposed within a physical space (102), such as a room, corridor,hallway, or doorway. In the depicted embodiment of FIG. 1, an indoorspace (102) is used, but the systems and methods described herein areoperable in external environments as well. In the depicted embodiment, anode (107A) is communicably coupled (111) to a telecommunicationsnetwork (115), such as an intranet, an internet, or the Internet. Aserver computer (109) may also be communicably coupled (113) to thetelecommunications network (115) and thereby with the connected node(107A). The depicted server (109) comprises programming instructions forimplementing the systems described herein, and carrying out the methodsteps described herein. However, in an embodiment, the functionsperformed by the server may be performed by one or more nodes (107)having the appropriate software/programming instructions, or beingappropriately modified.

In the depicted embodiment of FIG. 1, each of the nodes (107) iscommunicably connected with at least one other node (107) in thedetection network (103), and may be communicably connected to two ormore, or all of the other nodes (107) in the detection network (103).For example, in a typical wireless network deployment strategy, aplurality of wireless access points is placed throughout the physicalspace (102), generally to ensure that a high-quality signal is availableeverywhere. These nodes (107) collectively form a detection network(103) and may transmit data to one another, or may transmit only to arouter or set of routers. In the depicted embodiment of FIG. 1, node(107A) is a wireless router, and the other nodes (107B), (107C) and(107D) are wireless access points. However, this is just one possibleconfiguration. Further, it is not necessary that any given node (107) bea particular type of wireless device. Any number of nodes (107) maycomprise a router, access point, beacon, or other type of wirelesstransceiver. Further, any number of nodes (107) may be present in anembodiment, though a minimum of two is preferred. More nodes (107) in aspace (102) increases the amount of data collected (as describedelsewhere herein), thus improving the chance that a human is generallyinterposed between at least two nodes (107), improving the locationresolution.

In the ordinary course of operation, the nodes (107) frequently send andreceive wireless transmissions. For example, when a wireless router(107A) receives a data packet, the wireless router (107A) typicallybroadcasts a wireless transmission containing the packet. This meansthat any receivers within the broadcast radius of the router (107A) canreceive the signal, whether or not intended for them. Likewise, when anaccess point receives local data, such data is likewise broadcast andcan be detected by other access points, and the router. Even when nouser data is actively transmitted on the network, other data isfrequently transmitted. These other transmissions may include statusdata, service scans, and data exchange for functions of the low-levellayers of the network stack.

Thus, each node (107) in a typical detection network (103) receivestransmissions on a consistent basis and, in a busy network, thiseffectively may be a continuous basis. The detection network (103) maythus be used to calculate the existence and/or position of a biologicalmass (104) or (105) physically interposed within the transmission rangeof the network (103). Because the presence of a human body impacts thecharacteristics of signals transmitted between or among nodes (107)within the network (103), such presence can be detected by monitoringfor changes in such characteristics. This detection may also beperformed while the data in the data packets being transmitted andreceived is still being transmitted and received; that is, the detectionis incident to ordinary data exchange between or among two or morenodes, which continues regardless of the detection. Specifically, thewireless network may operate to transfer data between nodes, whilesimultaneously using characteristics of how the data packetsincorporating that data have been impacted by the presence of an objectin the transmission path, to detect and locate the object.

In the depicted embodiment of FIG. 1, at least one node (107) monitorsthe communication signatures between itself (107) and at least one othernode (107) for statistically significant changes in signalcharacteristics even while it awaits, receives, and/or transmitscommunications between itself and other nodes (107). The particulargeometry of the physical space (102), including the presence andlocation of fixtures in the physical environment, generally does notimpact the system because the monitoring is for statisticallysignificant change in signal characteristics indicating or evidencingthe characteristics of a human. That is, a change in signalcharacteristics is attributable to a change in absorbers or reflectors,like human bodies, in the physical environment or communication spacecovered by the detection network (103). The detection of the presence ofa human within the detection network (103) may be done using statisticalanalysis methods on the signal, such as using sensing algorithms, asdescribed elsewhere herein. Again, this does not require the human to beassociated with a fiducial element, or in motion. Instead, the detectionnetwork (103) detects that characteristics of the network communicationhave changed because a new object (which is generally a human object)has been introduced in the communication space and the presence of thatobject has caused a change to the characteristics of the networkcommunications, typically data packets, between nodes (107).

To detect a change, generally a baseline of signal characteristics isdeveloped against which recently transmitted signals are compared. Thesecharacteristics are derived from typical wireless communication networkdiagnostic information. This baseline of signal characteristics betweennodes (107) is generally established prior to the use of the detectionnetwork (103) as a detector. This may be done by operating the detectionnetwork (103) under typical or normal circumstances, that is with thedetection network (103) communicating data packets, with no significantbiological mass interposed in the physical broadcast space of thedetection network (103). For an amount of time during such operation,signal characteristics between and/or among nodes (107) are monitoredand collected and stored in a database. In an embodiment, the server(109) will receive and store such data, but in an embodiment, one ormore nodes (107) may comprise hardware systems configured to receiveand/or store such data.

For example, where a node (107) contains special purpose hardware andprogramming for use according to the present disclosure, such node (107)may store its own signal characteristic data. Such signal characteristicdata may be data relating to the received energy characteristic ofsignals received by a particular node (107) from one or more other nodes(107). The baseline data establishes for each node (107) a signaturecharacteristic profile, which is essentially a collection of datadefining the typical and/or general characteristics of signals receivedby the node (107) under ordinary operating circumstances where there isno significant biological mass interposed in the detection network(103). The node (107) may have one or more of such profiles for eachother node (107) from which it receives data.

In an embodiment, after the baseline signatures have been detected andcollected, the detection network (103) will generally continue tooperate in the same or similar fashion, but is now able to detect thepresence of a biological mass. This is done by detecting and collectingadditional signal characteristics, generally in real-time, as thedetection network (103) operates in a normal mode of transmitting andreceiving data packets. These newly generated real-time signalcharacteristic profiles are also generally characteristics of signalsbetween two particular nodes (107) in the detection network (103), andthus can be compared to a corresponding baseline signal characteristicprofile for the same two particular nodes (107). A statisticallysignificant difference in certain characteristics between the twoprofiles may then be interpreted as being caused by the presence of asignificant biological mass, such as a human.

The comparison operations may be performed by appropriate hardware in agiven node (107), or the real-time signal characteristic profiles may betransmitted to a server (109) for processing and comparison. In afurther embodiment, both are done so that a copy of the real-time datais also stored and accessible via the server, effectively providing ahistory of signal characteristic profiles.

This is because, as described herein, a biological mass interposedwithin the network will generally cause at least some signalcharacteristics between at least two nodes to change when a data packetis transmitted which intercepts and/or generally interacts with thebiological mass. The degree and nature of the change generally will berelated to the nature of the particular biological mass interposed(e.g., the size, shape, and composition), and its location in thenetwork (103). For example, where a housefly flies through the detectionnetwork (103), the amount of signal change may be so minor as to beindistinguishable from natural fluctuations in signal characteristics.However, a larger mass, such as a human, may cause more substantial andstatistically significant changes in signal characteristics.

Such changes may not necessarily manifest in all signal characteristicprofiles for the detection network (103). For example, where the mass isinterposed at the edge of the detection network (103), the nodes (107)nearest that edge are likely to experience statistically significantsignal characteristic changes, whereas nodes on the opposing side of thedetection network (103) (whose signals to each other do not pass throughor around the biological mass), are likely to experience few or nostatistically significant changes. Thus, if the physical locations ofthe nodes (107) are also known, the system can determine not only that abiological mass is present in the detection network (103), but calculatean estimate of where it is located, by determining which nodes (107) areexperiencing changes and calculating the magnitude of those changes.

This can be seen in the depicted embodiment of FIG. 1. In FIG. 1,assuming the presence of only one human—either A (104) or B (105)—ispresent at a time for simplicity, A (104) would generally have a greaterimpact on the signal characteristics between nodes (107C) and (107A)than between nodes (107A) and (107C). Further, A (104) would alsogenerally have a small bidirectional effect on the signalcharacteristics between nodes (107B) and (107D). By contrast, B (105)would have a bidirectional impact on the signal characteristics betweennodes (107A) and (107C), as well as on the signal characteristicsbetween nodes (107B) and (107D).

While all nodes may be communicating with one another, the effects of A(104) and B (105) will generally be more negligible on communicationswhere A (104) and/or B (105) are not generally in line with thecommunications path between nodes. For example, neither person (104) or(105) is likely to seriously impact transmission between nodes (107A)and (107B) because neither person (104) or (105) is in the transmissionpath between those nodes. However, A (104) may have an impact ontransmissions between nodes (107C) and (107D).

It should be noted that the presence or absence of a biological masswithin the communication area of the detection network (103) will notnecessarily result in any change in data communication. It is expectedthat the detection network (103) will utilize its standard existingprotocols, means, and methods (including all forms of retransmission anderror checking) to make sure that the data in the data packets beingtransmitted is correctly received, processed and acted upon. In effect,the detection process of the detection network (103) is performed inaddition to the standard data communication of the detection network.

It should be recognized from this that the data in the data packetsbeing communicated by the nodes (107) in the detection network (103)generally will not be directly used to detect the biological mass withinthe communication area of the detection network (103). Instead, the datawill simply be data being communicated via the detection network (103)for any reason and will often have nothing to do with detection of thebiological mass. Further, while this disclosure generally contemplatespacketized communication in the form of data packets, in an alternativeembodiment, the data may be continuously communicated in anon-packetized form.

In an embodiment, in order to allow the detection network (103) todetect the presence or absence of a particular biological mass, thesystem includes a training aspect or step. This aspect may comprise,after the baseline is established, one or more humans are deliberatelyinterposed in the network at one or more locations in the network, andone or more additional sets of baseline data are collected and stored.This second baseline may be used for comparison purposes to improveaccuracy in detecting the size, shape, and/or other characteristics of abiological mass interposed in the network, and/or for improving theaccuracy of location determination. Such training may use supervised orunsupervised learning, and/or may utilize techniques known to oneskilled in the art of machine learning.

In an embodiment, a detection network (103) may use a specializedprotocol comprising a controlled messaging structure and/or format,which can be controlled from one node (107) to another (107), making itsimpler and easier to determine from which node (107) a messageoriginated, and allowing for control of aspects such as the compositionof the signal sent, transmitted signal strength, and signal duration.Such control further facilitates certain improvements in processing, andfacilitates receivers identifying and using certain signal qualitiesand/or characteristics particular to the detection aspects of thenetwork (103), which may differ from general networking aspects sharingthe same network (103). With control of the message sent and received onthe opposing sides of the mass being located, it is not necessary tosend a signal as a scan, nor to sweep a region in space, as suchfunctions tend to require significantly more expensive equipment than isneeded for typical broadcast or directional transmission between nodes(107). Messages are generally constructed in such a way as to bestproduce usable data for detection algorithms which would be constructedto function best with the communication network they are being usedwithin. Generally, such constructions still avoid the need for waveformlevel analysis of the signals sent by the network.

In the depicted embodiment, each node (107) generally is able todetermine the origin node (107) of packets received by such node (107).Such message origination information is typically encoded within themessage itself, as would be known to one skilled in communicationsnetworks. By way of example and not limitation, this may be done byexamining data embedded in established protocols in the networkingstack, or by examining data transmitted by the sending node (107) forthe specific purpose of implementing the systems and methods describedherein. Typically, each node (107) has appropriate hardware andprocessing capability for analyzing the messages received. While manydifferent topologies and messaging protocols would allow for thefunctionality described herein, generally mesh networking topologies andcommunication methods will produce usable results.

FIG. 2 depicts an embodiment (201) of a method according to the presentdisclosure and should be understood in conjunction with the system ofFIG. 1. In the depicted embodiment, the method begins (203) with theestablishment (203) of a detection network (103) comprising a pluralityof communication nodes (107) according to the present disclosure. Aswould be known to one skilled in the art of setting up communicationsystems, there are many different approaches to the setup of such anetwork (103) and many different network (103) topologies may proveviable within this framework.

Next, a digital map in memory may be generated (205) indicating thedetection network's (103) physical node (107) geometry. The detectionalgorithms described herein generally use information about where in thephysical environment (102) the nodes (107) are deployed. Data about suchphysical location of the nodes (107) may be supplied manually to anaccurate diagram of the physical network environment (102), and/orsoftware could be used to automatically generate a relational positionmap of one or more nodes (107) within the detection network (103),facilitating easier placement of the nodes (107) into such anenvironment map or diagram.

Alternatively, nodes (107) may be placed on a blank or empty map ordiagram using relational (as opposed to absolute) distances fordetection. In such a dimensionless system, messages could still begenerated from the algorithms related to the detection of humans in thesystem (101), and additional manual processing may be included, such asuser input concerning which messages are sent related to the presenceand/or movement of humans within the network (103).

In an embodiment with automatic node (107) location detection, node(107) locations are detected algorithmically and/or programmatically byone or more nodes (107) and/or a computer server (109), based uponfactors such as, but not necessarily limited to: detection network (103)setup and configuration, including physical location of specifichardware components such as nodes (107) and each node's (107) locationrelative to one or more other nodes (107); signal strength indicators;and, transmission delay. In the depicted embodiment, this step (205)further comprises overlaying the generated map on a digital map of thephysical space (102) or environment (referred to herein as an“environment map”) the detection network (103) occupies, such as floorplan of a building. This step (205) may further and optionally comprisea scaling element to align the scales of the generated map to theenvironment map, as well as user-manipulated and/or modifiable inputelements for making adjustments to fine-tune the generated map so thatit more closely conforms to the actual node (107) deployment geometry,as would be understood by one of ordinary skill in the art. In analternative embodiment, each node (107) may be manually placed in itsappropriate location on the environment map without using a relativelocation algorithm.

Either way, this step (205) establishes the physical locations of thenodes (107) in the detection network (103), which will facilitatedetermination of the location of interposed biological massesattributable to the presence of humans within the detection network(103). By placing the nodes (107) on a map (either through manual orautomatic means), the nodes (107) can track the presence of a human inthe network (103) based on how the baseline signal affects communicationbetween various nodes (107). The system (101) then utilizes informationcollected about the signals which arrive at the receivers, given atransmitted set of information known to the data processing algorithm.The data processing algorithm is what ultimately determines whether ahuman is present within the network (103) and/or where within thenetwork (103) that human is located.

Next, messages are constructed and exchanged (207) in a format, andaccording to a protocol, determined to be suitable for detecting thepresence of a biological mass within the network (103). While this maybe done using general purpose networking protocols known in the art,such as protocols in the OSI network model, or special-purpose protocolswhich replace, or supplement, such general-purpose protocols.

Generally, it preferred that this step further comprise controllingand/or modifying (207) messages passed within the detection network(103) for the specific purpose of detecting human presence andfacilitating simplified statistical analysis. By controlling (207)message exchange, the system (101) can adjust for a common content beingsent through the detection network (103) while also facilitatingadjustment of parameters including, but not necessarily limited to:transmission intervals; transmission power; message length and/orcontent; and, intended message recipient(s). Again, the system does notnecessarily rely on waveform level analysis, allowing operation withinthe confines of wireless communication standards.

Controlling (207) such parameters facilitates the development ofstatistics and/or analytics, which may be based at least in part onpre-defined or anticipated message content or characteristics. Suchcontent and/or characteristics may include, without limitation,transmission timestamp and/or transmission power level. By controllingand modifying (207) these aspects, one may overcome hardwarelimitations, including hardware features which cause unwantedconsequences when used in a detection network (103) according to thepresence disclosure, such as but not necessarily limited to automaticgain control (AGC) circuits, which may be integrated into certainreceiver hardware in a node (107).

Next in the depicted embodiment (201), the space (102) is cleared (209)of significant biological mass—notably humans (205). Then, a statisticalbaseline of signal strength is developed (211) locally by each node(107). Again, by placing the nodes (107) on a map in step (205), whetherthrough manual and/or automatic means, the nodes (107) can track thepresence of a human in the network (103) based on how the baselinesignal is affected for communication between nodes (107).

Next, a biological mass enters (213) the detection network (103),causing signal absorption and other distortions, which manifest inchanges in signal characteristics between nodes (107). These changes aredetected (215) and analyzed (217) to determine whether the changes areindicative of the presence of a human, or of another type of biologicalmass the detection network (103) is configured to detect. Suchdetections are further localized at least to an area between nodes, suchas within an interior area between three nodes on the network, butpossibly with greater accuracy depending on the algorithms and hardwarebeing in use at the time.

Generally, this is done using detection algorithms executed either byone or more nodes (107) or by a server computer (109). The nodes (107)and/or server (109) use software to estimate the location of thedetected biological mass in the detection network (103) using one ormore detection algorithms. Such algorithms generally compare thebaseline profile to newly detected signals, and may also use or be basedupon various data and other aspects, such as, without limitation:detection network (103) setup and configuration, including physicallocation of specific hardware components such as nodes (107) and eachnode's (107) location relative to one or more other nodes (107); signalstrength indicators; and, transmission delay.

Generally speaking, as described elsewhere herein, these algorithmsinclude comparing newly gathered signal characteristic profiles (215) tobaseline signal characteristic profiles (211) to identify a change anddetermine whether, based on the nature of the change, the change isindicative of the presence of a human. This determination may be done atleast in part using training data developed through machine learning asdescribed elsewhere herein.

In an embodiment, the detection algorithms may further comprise the useof observed signal characteristic change(s) between one or more pairs ofnodes (107) in the detection network (103), correlated in time andrelative effect. These factors facilitate the identification of aphysical location in the detection network (103) where such a signalchange took place, allowing for an estimate of the physical location ofthe human causing such signal characteristic change(s), which in turnmay be used to estimate a physical location in the detection network(103) environment where the biological mass is interposed. Such physicallocation may be provided as simple x, y, z coordinates according to acoordinate system, or may be visually indicated, such as on the map.

Where multiple humans are present in the detection network (103),separating out the impact of the various individuals from one another ismore difficult, and accuracy will generally improve with the addition ofmore nodes (107). In an embodiment, techniques such as advancedfiltering and predictive path algorithms may be used to separatelydetermine location of individuals within the network (103). Althoughmovement of the human in the network (103) is not required for thesystems and methods to operate properly, movement, or lack of movement,may be used to improve detection accuracy, such as by predicting thepath of a single individual. This can help identify instances where anindividual has, statistically, “disappeared” from the detection network(103) but the system has sufficient data to estimate that the individualis still present in the network (103).

For example, where an individual's movement path has been predicted, andterminates next to another detected individual, the system (101) maydetermine that the two individuals are too close together for signalcharacteristic profile changes to separately identify them, but sincethe individual's movement path was not determined to have taken theindividual out of the network's (103) detection range, the algorithmdetermines that the individual is present, and not moving, in closeproximity to another detected human. Thus, when one of the twoproximate, stationary humans moves, the algorithms may again separatelyidentify each one, and resume predicting path based on observed signalcharacteristic profile changes.

In this way, the systems and methods according to the present disclosurecan track one or more individual humans within a network (103), whetheror not moving, and whether or not any such humans are associated with afiducial element. Identifying specific individuals may further be doneusing other path prediction and sensing algorithms, such as but notnecessarily limited to those used in the robotics industry forhuman-following technology, in order to estimate which human was which.It should be noted that individuals may impart specific and uniqueeffects on various signal characteristics, allowing for theidentification of a specific individual, and further allowing for onespecific individual to be distinguished from others. Such effects may beused to further determine the location of specific individuals withinthe detection network.

The detection algorithm(s) are generally constructed to take advantageof the characteristics of communication signals, considering factorssuch as, but not necessarily limited to, frequency of the signal(s) andthe transmitted power levels of the signal(s). In an embodiment, thealgorithms detect human presence using data-driven methods fordetermining the effect of the presence of a human on signalcharacteristics in the RF environment within the communication network,and then identifying when that effect is later observed.

For example, in an embodiment, a signal characteristic which varies withthe presence of a human body is the signal strength registered betweennodes (107). This is particularly the case within a BLE network, and thestatistics related to signal strength over time may indicate thepresence of a human within the network. These artifacts may be used bythe detection algorithm(s) to provide information about the physicallocation of the object causing the artifact. That is, by combiningvarious statistics about artifacts captured across the network (103),the system determines where in physical space (102) the artifact islocated, and thus where a human is in the network (103).

In the simplest use case, the algorithms may simply identify changes insignal characteristics which are similar to changes known (e.g., fromtraining) to be caused by the presence of a human, and simply trigger adetection event (219) whenever such changes relative to a baseline aredetected. This may appear like an adjustment of mean, standarddeviation, skewness, or variance in the signal strength depending on thesystem (101) used. When the detected signal characteristic profilereturns to a profile similar to the baseline, it can be inferred thatthe physical environment (102) has returned to an empty state withrespect to whether a human is present.

Elaborating on the simplest use case, the baseline profile in this casecomprises some or all baseline profiles which exist when a space doesnot contain any humans, and may vary depending on physical adjustmentsto that space. Simpler algorithms, which may account for the changesassociated with a newly detected human change relative to a recentbaseline, can be used to address such situations; however, in the eventthat the baseline has changed, it is preferred that the systemaccurately determine whether one or more current signal profiles matchesan empty baseline profile, or matches a profile one that represents somedegree of occupancy. Such determinations may be made in response tomovement, but it is preferred that they be not made in response tomovement, but rather based on whether the characteristics of such asignal can be correlated with one or more of the empty baselines or oneor more of the presence signal profiles.

Compared to other technologies used for such determinations (typicallythe Passive Infrared (PIR) Sensor), which require motion to function,the systems and methods described herein are capable of detecting thepresence of a static human within a space (102), whether or not inmotion, and more precisely, detecting when a human is no longer in thespace (102). For applications such as security and occupancy sensing,this system would be more difficult to trick. Some examples of tricksthat may fool PIR and other similar motion based technologies includeholding a sheet in front of a person while they enter a space, movingvery slowly, or remaining generally motionless in an area afterentering. Another benefit is that the system does not necessarilyrequire additional hardware beyond that used in ordinary networkcommunications. This is because the additional software and processingcapability may be provided via external components or modifications toexisting hardware, such as by implementing the appropriate software as aSystem On a Chip (SOC) attached to off-the-shelf communications modules.If additional processing power is required, additional processingnode(s) may be added to analyze the signals propagated between nodes(107), or the workload may be transmitted to and handled by a dedicatedserver machine (109).

Making determinations of human presence and/or location may be relatedto the particulars of the signal type being analyzed, and controllingthe signal sent between nodes (107) on the network (103) to best achievethose detections. By sending controlled communication pulses through thenetwork (103) where the original signal is known and the transmittedpower can be modulated, it is possible to develop exemplary data relatedto signal absorption, reflection, backscatter, etc. due to additionalhumans between the nodes (107). Since it is generally assumed that abaseline system can be configured without the presence of a human andthat such a baseline would look statistically different than with ahuman present, it can further be assumed that signal characteristicchanges would be due to the presence of a human in the network. Byallowing for the input of timers and generally configuring the system torefine the baseline definition when a space (102) is empty, the systemmay recalibrate itself periodically to achieve improved accuracy.Generally speaking, tracking algorithms make use of the best availabletriangulation calculations combined with statistical methods, as wouldbe known to one skilled in the art of location technologies, coupledwith the detection algorithms for detecting humans within the network(103).

The present disclosure does not require a fiducial element associatedwith the human detected, nor does it require that the human be carryingany device capable of communicating with the network; however, suchtechnology would take advantage of such elements should they be deployedwithin the system. The addition of such elements may ease thecalculation burden on the system and allow for increased accuracy. Thesystems and methods described herein do not preclude such additionalfunctionality, and could be enhanced by it. Augmenting detection with aninference engine adds to the ability of the sensing hardware to recoverfrom a false alarm situation or other edge case, thereby making thesystem more robust. Such an inference engine may further feedinformation into a machine learning system, which may further modify theone or more baseline signal profiles or the one or more presence signalprofiles to improve the performance of the system.

In an embodiment, a detection network (103) implementing the systems andmethods described herein may further comprise elements for taking action(219) based on the detected presence and/or location of a human. Thismay be done, for example, by sending control signals over the networkusing the computers to first determine the presence and/or location of ahuman on the network, and then to determine an action to take based onthe presence and/or location of a human on the network, and to send amessage over that network to take that action. Since the communicationnetwork and the network performing the detection may be the samenetwork, the invention described herein extends the traditionalfunctionality of a communication network to include human detectionand/or location sensing without requiring additional sensing hardware.

The computer elements on the network necessarily perform additionalcalculations and may craft communication signals. This may ease thecalculation burden on the computers; however, the network may stillfunction as a command and control network, independently of the networkas a detection network.

The system as a whole can be used for a wide variety of applications,ranging from occupancy sensing, as might be used for lighting controland/or security, to counting the number of people in a space as might beneeded for a heat and/or traffic map, to a system that tracks individualhumans moving through a space. The technology may be integrated into thenetwork nodes themselves, or may be a combination of nodes transmittinginformation to a processing element (either directly on the network orin the cloud) to perform the calculations to determine the desiredinformation. The final integrated product suite may be customized for anapplication, and could be used in a variety of different ways.

No additional sensor is required (though, in an embodiment, one may bepresent), and the detections are effectively made through calculatingstatistics from the traditional RF communication stack. Such a systemprevents the collection of personal data from the people walking throughthe space as the system only knows that an approximately human-sizedmass of water, organs, clothing, etc. has passed through, and does notrequire any separate device to act as a fiducial element. As such, thetechnology represents a significant departure from traditional methodsfor tracking humans moving through a space.

A logical extension of the systems and methods described hereincomprises dynamically handling functional network messages within thestatistical analysis so as to avoid or reduce additional messagingoverhead for the system. It is also contemplated that, in an embodiment,the systems and methods described herein are extended to comprisedynamic adjustments to network and/or message structure, configuration,and/or operating parameters based at least in part on functionalmessages transmitted within the network.

Further, because the tracking is based on signals being affected by whatis generally a human mass, the system is not reliant on the human movingaround for detections. By not relying on movement, many of theshortfalls with traditional presence sensing technologies, such aspassive infrared and ultrasonic sensing technology, are overcome.

The utilization of a communication network's signals between nodes todetect the presence of humans in the network where the human does notcarry a fiducial element is a radical departure from currentnon-fiducial element detection methods and makes use of communicationnetworks to perform presence sensing in an entirely new way. Thecombination of detection techniques and utilization of network nodes astransmitter receiver combinations for the purposes of performing humanpresence detection presented herein constitute a new type of humanpresence detection system which does not require additional equipmentbeyond that which is required to form the communication network itself.

The systems and methods described herein may be implemented in acommunication network without influencing the operation of the networkitself for purposes of ordinary communication. The network continues tooperate as a communications network as its primary function, but some ofthe communications are used in this case to calculate the position of ahuman existing in the network. Because the systems and methods describedherein utilize basic operations of a network, a human within the networkadditionally carrying a transceiver device known to the network may bedetected and located with increased accuracy. Such a transceiver device,which may comprise, for example, a mobile computing device having awireless transceiver, such as a cell phone, mobile phone, smart phone,tablet computer, wearable computer technology, and so forth, may connectto the network and be locatable by the network using traditionaltriangulation methods known to one skilled in the art. Machine learningalgorithms may also be applied when a person carries such a transceiver,which may in turn further improve performance.

The location calculation of a known transceiver device may be comparedwith the location of the person as determined by the non-transceiveraspects described herein. With the communications network reporting boththe location of the fiducial element as well as the human within thenetwork, the locations of those two can be compared. Since it isgenerally the case that the detected location of a fiducial element hasa higher degree of fidelity than the estimated location of the humanbased on network communications alone, the location calculations for theposition of the human within the network can be adjusted using machinelearning algorithms so as to improve the location calculationcapabilities of the system for the next human entering the network.

Using machine learning algorithms, the system can improve the accuracyof location predicting algorithms based on the known location from thetransceiver. This may allow for verification of prior determinations,and refining of future determinations. For example, if it is found thatprior determinations are consistently off by about the same amount, thatamount may be applied to future determinations as an adjustment. In thisway, the system can continue to improve and train itself to betterlocate the humans within the network. Similarly, machine learning cancontinue to improve the detection and false alarm rate. By way ofexample and not limitation, data concerning prior traffic patterns at afacility can be used to establish defaults, presumptions, orexpectations concerning the range of times or days during which aparticular facility is generally occupied or generally empty. Such datacan be used by the system to improve its performance.

Additionally, the system is configured to make or draw inferences, suchas based upon physical interactions with network elements; that is,devices or components attached to or communicating with the network thatare operable by or operate based upon the presence of a human, such asnetwork-operable electrical switches, doors, motion sensors, infraredsensors, and the like. Such physical interactions may be consideredfiducial elements at the point in time that they are interacted with forthe purposes of the system. As an example, if a light switch that ispart of the network is actuated, the system may infer that a human waspresent at or near the physical location of the switch at the time theswitch was actuated. As such, the system could use that information as aknown data point (i.e., examining signal characteristics of the variousnetwork devices at that point of time with the inferred knowledge thatthose characteristics reflect a human at a particular location near theswitch) to which it could apply machine learning to better makepredictions of human presence in the future. Additionally, such eventscould serve as presence triggers for other purposes such as securityalerts. As an example, say that the system is in a security mode andsomeone has found a way to mask their presence but still interacts witha switch, then the system would be able to determine that someone waspresent and send an alert based on the interaction with the switch.Generally speaking, interactions with the system would be defined bothphysically and logically where logical interaction would include typicalusage patterns based on time, outside inputs, etc. Such a system servesas backup to the RF presence sensing and provides additional machinelearning capabilities to the system.

Additionally, the system can estimate whether a mobile transceiver inthe network is actually being carried by a human or not, such as where ahuman leaves a device in a location in the network. Because the systemcan detect the human as a biomass through changes in signalcharacteristics, the system can detect whether a transceiver is presentin the network while a human biomass is not. This inhibits falsetraining of the system and facilitates the avoidance of baseline andpresence signal profiles being corrupted by data not correlated withsuch profiles.

In an embodiment, as a further input to the inference engine, if someindication of the system changes states, and a human within thedetection area behaves in such a manner as to correct the system state,the system may infer that it should adjust its baseline and presenceprofiles to better reflect user preferences. By way of example, if thelights in a space were to turn off with a human in the space, said humanmay engage in behavior to reflect presence, such as physically moving,waving arms, and so forth, or simply looking for or walking towards awall switch. This movement may be detected within some reasonable amountof time, and the system may determine that it incorrectly determinedthat the space was absent, and adjust its baseline and presence profilesaccordingly. Such activities may be referred to as inferring thepresence of one or more humans in a space.

As a side effect of collecting various signal characteristics and beingcapable of running them through various algorithms, the system iscapable of running multiple detection calculations simultaneously toachieve different performance criteria with the same system. As anexample, the same communication network can be used for detectionsassociated with lighting and security; however, the gathered statisticscan be processed differently, but simultaneously, for the twoapplications. In this way, the lighting application can still providefor a shorter time to detect, but with a potentially higher false alarmrate, while a security application can trade a slightly longer time todetect while reducing the false alarm rate. The signal characteristicsto be processed by the system may vary by application, but all arecaptured from the communication network and can be processed in multipleways simultaneously. Such processing methods may be encapsulated inmultiple sets of different sample baseline signal data for determiningdetections relative to a baseline signal profile.

In an embodiment of a system according to the present disclosure, thesystem comprises a communication system which is capable of determiningthe presence of one or more humans from information about the wirelesssignals between two or more computers on the network where each computerconsists of: a transceiver for communication; and a computing elementfor performing calculations, where each computer sends signals to one ormore other computers on the network where the signal includes a uniqueidentifier of the computer sending the signal; where each computerprocesses the signals received for the purposes of determining thepresence of one or more humans; and where the one or more humans are notrequired to have on their person any device capable of communicatingwith the network.

In an embodiment of such a system, the algorithms use statisticalmethods to determine the presence of one or more humans. In a furtherembodiment of such a system, the statistical methods determine thenumber of people present. In another further embodiment of such asystem, the system is capable of determining the physical location ofthe one or more humans on the network. In a still further embodiment ofsuch a system, the system is capable of tracking the physical locationof the one or more humans over time. In another further embodiment ofsuch a system, the system uses information about the presence of one ormore humans to control devices on the network. In an embodiment, thenetwork is a mesh network.

In an embodiment, the computers determine their relative physicallocations and further determine the relative physical location of theone or more humans on the network. In a further embodiment, statisticalmethods are applied to a measure of signal strength to determine thepresence of a human. In a further embodiment, the transmitted signal iscontrolled for making detecting human presence easier. In a furtherembodiment, the power level of the transmitted signal is controlled formaking human presence easier. In a further embodiment, the systemfunctions as an occupancy sensing system. In a further embodiment, theoccupancy sensing system controls a lighting system. In a furtherembodiment, the network for controlling the lighting system and thenetwork used for occupancy sensing utilize the same communicationstechnology and hardware. In a further embodiment, the communicationstechnology employed by the computers is chosen from the list of:Bluetooth™ Low Energy, WiFi, Zigbee, Thread, and Z-Wave.

In a further embodiment, the system functions as a sensing system for asecurity application. In a further embodiment, the security sensingsystem controls the security system. In a further embodiment, thenetwork for controlling the security system and the network used forsecurity sensing utilize the same communications technology andhardware. In a further embodiment, the system functions as a humandetector for robotic systems. In a further embodiment, the roboticsystems have computers which locate various elements of the roboticsystem relative to one another dynamically. In a further embodiment, thenetwork for controlling the robotic systems and the network forfunctioning as the human detector for the system utilize the samecommunications technology and hardware.

In a further embodiment, the system functions as a sensing system for aHVAC application. In a further embodiment, the HVAC sensing systemcontrols the HVAC system. In a further embodiment, the network forcontrolling the HVAC system and the network used for HVAC sensingutilize the same communications technology and hardware.

In another embodiment, the system uses machine learning to improve itsdetection capabilities where humans which have a fiducial element ontheir person train the system through: (1) using known locationtechniques to determine the location of the fiducial element; (2) usingthe system described above to locate the person; (3) comparing thelocation calculated by the method of (1) of this paragraph to the methodof (2) of this paragraph; (4) adjusting the location determining methodsusing machine learning algorithms to improve the location calculatingcapabilities of the system.

In another embodiment, the system may infer the presence of humans inthe network based on those humans interacting in some way with one ormore of the computers on the network. In a further embodiment, thesystem may use the inferred presence of a human as an input for machinelearning to improve its detection capabilities.

In an embodiment of a system according to the present disclosure, thesystem comprises a communication system which is capable of determiningthe presence, both static and moving, of one or more humans frominformation about the signals between two or more computers on thenetwork where each computer consists of: a transceiver forcommunication; and a computing element for performing calculations,where each computer sends signals to one or more other computers on thenetwork where the signal includes a unique identifier of the computersending the signal; where each computer processes the signals receivedfor the purposes of determining the presence of one or more humans;where the one or more humans are not required to have on their personany device capable of communicating with the network.

In an embodiment, the algorithms use statistical methods to determinethe presence of one or more humans. In another embodiment, thestatistical methods determine the number of people present. In anotherembodiment, the system is capable of determining the physical locationof the one or more humans on the network. In another embodiment, thesystem is capable of tracking the physical location of the one or morehumans over time. In another embodiment, the system uses informationabout the presence of one or more humans to control devices on thenetwork. In another embodiment, the information about the presence ofone or more humans is made available to one or more systems not directlyinvolved in the determination of presence. In another embodiment, thesystem has the ability to perform self-optimization to achieve a givenperformance according to one or more preset criteria.

In another embodiment, the communications protocols or network isgenerally defined by a standards committee including but not limited toprotocols such as Bluetooth™ Low Energy, WiFi, Zigbee, Thread, andZ-Wave. In another embodiment, statistical methods are applied to ameasure of received signal strength to determine the presence of ahuman. In another embodiment, the transmitting and receiving devices onthe network may be selected and actuated by the system for the purposeof making human detection easier. In another embodiment, the power levelof the transmitted signal may be controlled for making human presenceeasier. In another embodiment, the system functions as an occupancysensing system for a lighting system. In another embodiment, theoccupancy sensing system controls a lighting system. In anotherembodiment, the network for controlling the lighting system and thenetwork used for occupancy sensing utilize the same communicationstechnology and hardware.

In another embodiment, the system functions as a sensing system for asecurity application. In another embodiment, the security sensing systemcontrols the security system. In another embodiment, the network forcontrolling the security system and the network used for securitysensing utilize the same communications technology and hardware. Inanother embodiment, the system functions as an occupancy sensor for aHeating, Venting, and Cooling (HVAC) system. In another embodiment, theoccupancy sensing system controls the HVAC system. In anotherembodiment, the network for controlling the HVAC system and the networkused for occupancy sensing utilize the same communications technologyand hardware.

In another embodiment, the system uses machine learning to improve itsdetection capabilities where humans which have a fiducial element ontheir person train the system through: (1) using known locationtechniques to determine the location of the fiducial element; (2) usingthe system to locate the person; (3) comparing the location calculatedby (1) of this paragraph to (2) of this paragraph; (4) adjusting thelocation determining methods using machine learning algorithms toimprove the location calculating capabilities of the system.

In another embodiment, the system may infer the presence of humans inthe network based on those humans interacting in some way with one ofthe computers on the network. Said interactions may be direct physicalinteractions or indirect interaction in response to some change of statein the system (e.g., waving arms in response to lights turning off). Inanother embodiment, the system may use the inferred presence of a humanas an input for machine learning to improve its detection capabilities.

Also described herein is a communication system which is capable ofdetermining the presence, both static and moving, of one or more humansin a detection network based on information about the signals betweentwo or more computers on the network where each computer consists of: atransceiver for communication; and, a computing element for performingcalculations, where each computer sends signals to one or more othercomputers on the network where the signal includes a unique identifierof the computer sending the signal; where each computer will process thesignals received for the purposes of determining the presence of one ormore humans in two or more ways to achieve different performancecriteria as required to function for two or more purposessimultaneously; where the one or more humans are not required to have ontheir person any device capable of communicating with the network.

In an embodiment, the algorithms use two or more statistical methods todetermine the presence of one or more humans according to two or moresets of performance criteria. In another embodiment, the system has theability to perform self-optimization to achieve a set of two or moreperformances according to two or more preset criteria. In anotherembodiment, the communications protocols or network is generally definedby a standards committee including but not limited to protocols such asBluetooth™ Low Energy, WiFi, Zigbee, Thread, and Z-Wave. In anotherembodiment, two or more statistical methods are applied to a measure ofreceived signal strength to determine the presence of a human accordingto two or more sets of performance criteria. In another embodiment, thesystem uses machine learning to improve the detection capabilities ofthe two or more methods for determining presence where humans which havea fiducial element on their person train the system through: (1) usingknown location techniques to determine the location of the fiducialelement; (2) using the system to locate the person; (3) comparing thelocation calculated by (1) of this paragraph to (2) of this paragraph;(4) adjusting the location determining methods using machine learningalgorithms to improve the location calculating capabilities of thesystem.

In an embodiment, the systems and methods described herein includechange detection. By way of example and not limitation, change detectionmay use or utilize a rolling baseline approach. In such an embodiment, afirst baseline is established and compared with a second baseline, andany differences between the first and second baselines caused by thepresence of a human in the detection network may be recognized by thesystem. This may be done by programming software to receive sets ofwireless signal characteristic data from one or more nodes in thedetection network and, based on such data, detecting changes in the RFenvironment caused by a human being present in a different position whenthe first baseline is established as compared to the second baseline.Such methods may be utilized when a system is first setup in a locationto establish a minimal performance level without requiring a space beempty upon startup. Such systems with change detection may improveovertime to a state between change and presence where limited aspects ofpresence detection may be present in such a system.

An exemplary illustration of change detection is depicted in FIG. 3A. Inthe depicted embodiment of FIG. 3A, the RF environment of FIG. 1 isshown with a human (301) present in the environment (103) at a discreetposition (303). As described elsewhere in this disclosure, thecharacteristics of wireless signal transmissions among the nodes (107A)to (107D) is influenced by the presence of the human (301). In thisparticular example, transmissions between node A (107A) and node D(107D) are influenced by the presence of the human (301). Thus, when thebaseline is established (211) as shown in the method of FIG. 2, thebaseline represents the wireless signal characteristics while the human(301) is present at the discreet position (303). If the human (301)moves to a new position (305), as can be seen if FIG. 3A, thecharacteristics of wireless signals among the nodes (107A) to (107D)will change.

In this particular exemplary embodiment, there will be littleinterference between nodes A (107A) and D (107D) when the human is atposition (305). However, there will be greater interference betweennodes B (107B) and C (107C), because the position (305) is disposedbetween those two nodes. Thus, when the differences are detected (205)as shown in FIG. 2, the change in position of the human can be detected.

This is less difficult to implement than presence sensing because theneed to establish baselines in the detection network (103) without ahuman present is reduced. Such a system may detect changes within thedetection network (103) based primarily on when a human changespositions, and updating the operative baseline profile on a rollingbasis. That is, the baseline (211) is updated in this embodiment to beequal to the baseline when the human (301) is at position (305). Thus,when the human (301) moves to a third position (307), the differencesdetected (215) are as between the second baseline taken at position(305) and the wireless signal characteristics of detection network (103)when the human is at position (307). Likewise, the baseline (211) hasbeen updated to be equal to the baseline in position (307), which canthen be used to detect further changes in the position of a human (201).This detection method uses changes in the wireless signal baselinescaused by changes in the position of a human (301) in the detectionnetwork (103). This system has many advantages over prior art motiondetection technologies, such as passive infrared, in that this system isnot obscured by objects and can detect slow or gradual changes inposition, which may be overlooked by prior art systems. In an embodimentusing this methodology, the baselines may be continuously updated.

In another embodiment, the system or method comprises making aconfidence determination. This aspect may determine a degree ofconfidence that a third baseline corresponds to either a first or secondset of baselines. The confidence determination may use any number oftechniques, including techniques known in the art, such as supervisedtraining or the use of statistical methods to determine a degree ofsimilarity or difference between data sets. The confidence may increaseor decrease over time, allowing for decisions to be automatically madewith respect to baseline differences that are minimally different, butmay still indicate the presence of a human in the detection network(103). Confidence in a determination of presence or absence of a humanin the detection network (103) may be determined based on how similar athird baseline is to a first or second baseline. For example, if a thirdbaseline is known to indicate the present of a mass whose impact onsignal characteristics is known, comparing the first or second baselineto the third may improve (or decrease) the confidence level that theidentified mass is the same as the mass identified in the thirdbaseline. Based on confidence, the system can be configured to usedifferent confidence thresholds in different operational contexts (e.g.,HVAC, security, lighting, safety, etc.). A system or method including aconfidence determination may operate across a plurality of systems usinga common communication system, wherein the systems can include disparatenodes in communication with one another. A given node may operate in aplurality of detection networks (103), allowing for better systemscaling when deploying the systems and methods to multiple adjacentdetection networks (103).

In another embodiment, baseline differences may be used to count orestimate the number of humans present in the detection network. In anembodiment, this may be done by estimating the amount of human mass inthe detection network, and dividing by an average mass per person. Thismay be done by establishing a first, empty baseline when there are nohumans in the detection network (103), and establishing a second,occupied baseline when some known number of humans are present in thedetection network (103). Next, a third baseline is taken and compared tothe first empty baseline and the second occupied baseline. The systemsoftware then interprets where the third baseline wireless signalcharacteristics fit on a spectrum of profiles between the first emptybaseline and the second occupied baseline, and from that determinationestimate the total amount of human mass in the detection network (103).This estimation may be based upon the total mass of humans in thedetection network when the second occupied baseline was established.

By way of example and not limitation, if the signal distortion in thethird baseline is moderate as compared to the first empty baseline, thesystem may estimate that the amount of human mass present is relativelylow. However, if the amount of signal distortion is closer to that shownin the second occupied baseline, the system may determine that theestimated amount of human mass present in the detection network (103) iscloser to the amount that was present when the second baseline wastaken. Similarly, if the amount of distortion is determined to be evenmore extreme than that reflected in the second baseline, the system maydetermine that the total amount of human mass present when the thirdbaseline was taken exceeds the amount present when the second baselinewas taken. The estimation of human mass may be based broadly upon thealgorithms and methods described herein, and adjusted to estimate anumber of humans in a space as generally described above.

In another embodiment, a system uses entrance and exit signatures innetwork diagnostic information to estimate the number of humans presentin a space based upon such signatures.

In such a method, an entrance profile is established by a human enteringa space, an exit profile is established by a human leaving the samespace, and another later-captured profile is compared to the entranceand exit profiles to determine whether a human has entered or exited thespace. Entrance and exit profiles are learned through normal systemoperation, based upon estimation from the presence detection technologyand its determination following a state change. By way of example andnot limitation, if a system detects a change and presence goes from notbeing detected to being detected, such an event may be classified as anentrance. Similarly, by way of example and not limitation, if the systemdetects a change and determines that a space has gone from occupied tounoccupied, such an event may be classified as an exit. The differencebetween entrance count and exit count may be used to estimate the numberof humans present in the space.

In another embodiment, a system uses entrance and exit signatures innetwork diagnostic information in combination with people countestimates derived from comparing a sample profile against presenceprofiles of varying people counts.

Each of these methods may be used in conjunction with one or morecounting methods to enhance the accuracy.

In an embodiment, the count or estimate of humans present in thedetection network (103) may be used to operate another system, such as,but not necessarily limited to, a HVAC system.

In an embodiment, the location or position of a human in the detectionnetwork is estimated. This may be done by estimating the range betweenvarious devices to determine the location of a human, examining subsetdetection areas constructed from higher numbers of nodes, using variouslocation baselines, and further extending the function of a locationsystem to analyze locations over time to estimate speed and direction ofa human in the detection network. In one embodiment of such a method,the system may use various node pairs, estimating the position of ahuman between those pairs based on baseline information, usingoverlapping estimates within the node pairs, then determining a highestprobability position for a human in the detection network based on thoseoverlapping estimates to determine the actual location of the human.

In another embodiment, systems with larger number of nodes can use moresubset detection areas, generally each with three or more nodes, todetermine the presence or absence of a human in each space, and estimatelocation based on overlapping occupied areas wherein the common occupiedspace might be assumed to be the most specific location of a human inthe detection network. By way of example and not limitation, a set offour nodes may be subdivided into four sets of three nodes, wherelocation may be determined based upon which subsets of three nodespresence is detected within. This sub-area creation allows fordetections within subareas where such sub-shapes are defined byoverlapping areas created with sets of three or more nodes.Alternatively, a plurality of baselines for humans in differentlocations within a detection network may be established, with subsequentbaselines compared against said baselines to determine the locationwithin the detection network of a human. By way of example and notlimitation, a detection profile may be created for various locationswithin a detection area where a given detection profile corresponds witha human in a given position within the network, a sample profile iscompared against a set of detection profiles corresponding to differentpositions, the system determines which detection profiles correlate mostwith the sample profile, and the system makes a determination of thelocation of the human based on the location of the detection profilesdeemed most similar to the sample profile.

Additionally, based on detected changes in locations of humans in thedetection network over time, a human's travel speed and direction in thedetection network may be estimated. This may be done, for example,through the use of interpolation and dead reckoning, or directreconnaissance. An exemplary embodiment of such a system and method isdepicted in FIG. 3B. In the depicted embodiment, a human is located in adetection network (103) at position (401) at Time₀. At a subsequentpoint in Time₁, the Human is detected at a different position (403).Because position (401) and position (403) are known, a Distance₁ betweenthem can be calculated. Additionally, the amount of time elapsed fromTime₀ to Time₁ can be determined or is known. Given that distance equalsrate times time, the rate of movement of the human from position (401)to position (403) can be determined. Additionally, a Vector could bedetermined representing the movement of the human, embodying bothdirection and magnitude (speed).

Having only two sample points, however, raises the possibility of a higherror rate, and more than two sample points is desired. For example, inthe depicted embodiment, a third profile taken at Time₂ places the humanat position (405). Again, the Distance₂ from position (403) to position(405) can be determined, and a rate of speed between these positions mayalso be determined. In the depicted embodiment, these positions aregenerally linear, suggesting that the human is moving in a more or lessstraight line in a given direction, defined by Vector. The system maythus further estimate the future or expected position of the human basedon this data. That is, at Time₃ an estimated position (407) of the humanmay be determined based on the prior detected locations. This estimatemay place the human outside of the detection network (103), and may befurther used to estimate the arrival or departure of a human in or fromthe detection network (103). Additionally, this information may be usedto alert another segment of the detection network, or another detectionnetwork entirely, of a potentially soon to be arriving human. This maybe done, for example, by communications using the computer server (109)via the network (115).

Continuing the exemplary embodiment above, in the depicted embodiment,the human's detected change in position from Time₀ to Time₁ is 0.8meters in one second, for a speed of 0.8 meters per second. The detectedchange in distance from Time₁ to Time₂ is 1.2 meters, with oneadditional elapsed second, or, 2.0 total meters over two total elapsedseconds, for an average speed of one meter per second. Thus, at Time₃,one second later, an additional one meter of movement may beanticipated, making the estimated future position (407) one meterfurther along Vector than position (405).

In an embodiment, the systems and methods use machine learning tofurther train the system over time. By way of example and notlimitation, a system may accumulate data from one or more of theabove-described change detection techniques using a combination of knownfeedback and/or feedback from third party systems such as but notlimited to interactions with other smart devices (thermostats, voicerecognition systems, etc.), and/or use inference over time to improveoperation based on expected or anticipated system behavior. Suchinferences may be based upon ordinary behavior in a space, direct humaninteraction with elements of the system, or sample profile changes fromhuman reactions to system decisions. By way of example and notlimitation, in a system implementing change detection to operatelighting or HVAC systems, user feedback may be provided to the system assupervised training data, indicating whether a given operation wascorrect (i.e., whether a change in the lighting or HVAC system shouldhave been made or not).

Similarly, in a system implementing presence detection, a user may forcechange detection to trigger while within a detection network, providingthe system an automated means to establish a baseline practice for theoccupied space based upon the time that change triggering events occurand, facilitating times far removed from change triggering events to bedetected as generally empty. When combined with inferring occupancybased on room type, such a method may facilitate the system trainingitself, improving functionality over time from change detection topresence detection level functionality. Effectively, by using the systembased on change detection, the system may infer presence and absence,allowing it to establish baseline profiles for when no human is presentand detection profiles based on when there is a human present. In such away, the system would be capable of training itself to move fromoperating as a change detection system into one operating as a truepresence detection system.

In an embodiment implementing counting, combinations of change detectionand presence detection may determine an estimated count of humans withina detection network, estimating such counting baseline profiles andimproving them over time. Such a system may facilitate the systemtraining itself over time to count the number of humans within thedetection network.

In an embodiment implementing locating people, combinations of changedetection, presence detection, and counting people may be utilized todetermine estimates of location based on overlapping areas and occupancycounts, eventually establishing more accurate baseline estimates,allowing the system over time to improve locating humans within adetection network. Such a system may comprise an inference engine, suchas computer software running on the server, and/or build an estimationof expected system operation from normal operations, and may adjustoperational parameters in accordance with expected behavior. Forexample, if a detection area is typically empty from 10:00 am until 3:00pm, and occupied from 3:00 pm until 6:00 pm, parameters may be adjustedto expect emptiness from 10:00 am-3:00 pm and to expect presence from3:00 pm until 6:00 pm). Such inferences may be developed over time andmay improve performance at those times, while maintaining overallflexibility.

Nodes may be disposed in various location combinations to improve systemoperation. A system may operate with nodes located on walls, ceilings,fixed nodes, mobile nodes, and/or in mixed configurations. Becausespaces are three-dimensional, detection areas may be defined by nodes ondifferent floors of a building. Nodes may be placed on walls inpositions such as switches and outlets. The broadcast range generallydefines the perimeter of a detection area, and the system may beconfigured to examine network diagnostics assuming humans are withinsaid perimeter.

In an embodiment, one or more nodes may be placed on a ceiling. By wayof example and not limitation, this might occur when nodes areintegrated into fixtures and/or lighting systems. In such an embodiment,nodes may radiate generally downward into the detection area, and asystem may be configured to examine network diagnostics based ondifferent radiation and multi-path patterns than might be seen from aswitch and outlet based system. In such an embodiment, nodes generatecommunications in a generally downward direction where reflections fromwalls, objects, and floors generally ensure that the RF energy reachesother nodes via multipath. The multipath also generally provides forcoverage of the detection area. Such coverage due to multipath meansthat ceiling mounted nodes function similarly to wall mounted nodes withregards to the impact of a human on network diagnostic information.

Other fixed nodes are also contemplated, such as, without limitation:televisions; monitors; and, smart home hubs. Such nodes may be installedon a wall, ceiling, or at a fixed location. Still other nodes, such assmartphones, tablets, and laptop computers, may be used in a detectionnetwork as a mobile node. However, in such an embodiment, a mobile nodemay first locate itself relative to fixed nodes in the system. Havingits location established within the network may further enhance theaccuracy of the system.

In an embodiment, combinations of nodes may be used in a detection area.When combining larger number of nodes, the system may determine theoptimal nodes for operation. Optimal nodes may be determined by, amongother things, determining the most efficient nodes for a chosen level offunctionality. As node count increases, accuracy of determinationgenerally increases, as does level of functionality.

In an embodiment, one or more nodes may operate in a plurality ofdetection areas. This facilitates improved system scaling, particularlyfor adjacent detection areas. Such scaling may additionally result ininference within a larger network of nodes including the plurality ofdetection areas, further facilitating the tracking of human detectionsfrom one detection area to the next. For example, nodes may be sharedbetween detection areas. A given node in a first detection network mayhave network diagnostic information based on communications within saidfirst detection area, and may also be part of a second detection networkand have network diagnostic information based on communications withinsaid second detection network. The system can make independent decisionson how to operate third party systems in each of the two detectionareas. Examining inference across detection areas can improve thedetermination of the presence or absence of humans within the detectionareas, particularly where a person leaves one detection area and entersanother. Detected changes in signal characteristics can be used todetermine the presence or absence of a human in the individual areas,based on information shared between the first and second detection area.

In an embodiment, the systems and methods may operate through the use ofa mass identification technique. In such an embodiment, a “mass” isidentified and tracked. A unique identity may be assigned to the mass bythe computer systems, and tracked based on changes to wireless signalcharacteristics. By way of example, and not limitation, if a mass isfirst detected near the center of a room, and next detected at alocation several feet away from the center of the room, but the systemhas not detected any other masses as entering the room, the system mayinfer that the second detected mass is the same mass as the firstdetected mass, but has relocated to a new position. Based on thedifference in signal characteristics caused by the interference of themass in the network, the system may infer, for example, that othermasses exhibiting similar movement would have similar effects on thesignal characteristics. In this way, the system can “learn” how toidentify a mass, and track it.

Although each human mass in the system causes different interferencecharacteristics when disposed at any location, for most indoorlocations, the total set of humans likely to be present in a room isgenerally finite. That is, most indoor spaces are, for any appreciablelength of time, occupied by the same basic set of people most of thetime, with only minor and infrequent variations. For example, the sameset of people generally show up each day to a workplace, or a school, oreven a public location such as a restaurant. Because most indoor spacescan only be entered from a limited number of points of entry, such asdoorways, the system can detect a person entering at the point ofingress, and determine the specific interference pattern caused by thepresence of that particular human upon entering the space. Based on thesignal characteristics (interference) and the way that thosecharacteristics change compared to other humans in the space, it can bedetermined where and how each human mass moves through the room.

It is contemplated that a system may automate various aspects of setup,particularly with regards to grouping nodes into detection areas andbuilding levels of functionality nominally based on the machine learningmethods described herein. A system which determines nearest nodes andestimates detection areas through inference requires no setup by a user.Based upon best estimates, a user may simply place nodes throughout abuilding, and the nodes automatically group into detection areas usingunsupervised machine learning, ultimately resulting in a building systemlearning how to detect occupants. Occupancy can then be related toactions taken by occupants, developing an automation system whichreduces or eliminates the need for human input for normal systemoperation.

In an embodiment, the method is a method for detecting the presence of ahuman comprising: providing a first transceiver disposed at a firstlocation within a detection area; providing a second transceiverdisposed at a second location within said detection area; a computerserver communicably coupled to said first transceiver; said firsttransceiver receiving a first set of wireless signals from said secondtransceiver; said computer server: receiving a first set of signal datafrom said first transceiver, said first set of signal data comprisingdata about properties of said first set of wireless signals; inferringthat said first set of signal data is indicative of the presence of ahuman in said detection area; creating a detection signal profile forwireless communications from said second transceiver to said firsttransceiver based at least in part on said properties of said first setof wireless signals in said first set of signal data when a human isinferred present in said detection area; said first transceiverreceiving a second set of wireless signals from said second transceiver;said computer server: receiving a second set of signal data from saidfirst transceiver, said second set of signal data comprising data aboutproperties of said second set of wireless signals; inferring that saidsecond set of signal data is indicative of the absence of any humans insaid detection area; creating a baseline signal profile for wirelesscommunications from said second transceiver to said first transceiverbased at least in part on said properties of said second set of wirelesssignals in said second set of signal data when the absence of any humansin in said detection area is inferred; said first transceiver receivinga third set of wireless signals from said second transceiver; saidcomputer server receiving a third set of signal data from said firsttransceiver, said third set of signal data comprising data aboutproperties of said third set of wireless signals; determining whethersaid third set of signal data is indicative of the presence of a human,or absence of any humans, in said detection area, said determining basedat least in part a comparison of said third set of signal data to saiddetection signal profile and said baseline signal profile.

In a further embodiment, the method comprises: in said inferring thatsaid first set of signal data is indicative of the presence of a humanin said detection area, said inferring is based at least in part onadditional signal data sets for signals received by said firsttransceiver from other transceivers in the detection area; and in saidinferring that said second set of signal data is indicative of theabsence of any humans in said detection area, said inferring is based atleast in part on additional signal data sets for signals received bysaid first transceiver from other transceivers in the detection area.

In a further embodiment, the method comprises: said computer serverstoring a plurality of historical data records indicative of whether ahuman was determined to be present in said detection area over a periodof time, each of said historical data records comprising an indicationof a number of humans determined to be present in said detection areaand a date and time when each of said number of humans was determined tobe present in said detection area; and said computer server making atleast some of said plurality of historical data records available to oneor more external computer systems via an interface.

In a further embodiment, the method comprises: said computer server isoperatively coupled to a second system; and only after said computerserver determines a human is present in said detection area, saidcomputer server operates said second system.

In a further embodiment, the method comprises: said first transceiverand said second system are configured to communicate using an identicalcommunication protocol.

In a further embodiment, the method comprises: said second system isselected from the group consisting of: an electrical system; a lightingsystem; a heating, venting, and cooling (HVAC) system; a securitysystem; and, an industrial automation system, an electrical system.

In a further embodiment, the method comprises: said wirelesscommunication utilizes a protocol selected from the group consisting of:Bluetooth™, Bluetooth™ Low Energy, ANT, ANT+, WiFi, Zigbee, Thread, andZ-Wave.

In a further embodiment, the method comprises: said wirelesscommunications from said second transceiver to said first transceiverhave a carrier frequency in the range of 850 MHz and 17.5 GHz inclusive.

In a further embodiment, the method comprises: said computer serverdetermining whether said third set of signal data is indicative of thepresence of a human includes a confidence metric.

In a further embodiment, the method comprises: said first transceiverand said second transceiver are configured to calculate their relativepositions within said detection area automatically.

In another embodiment, the method comprises a method for estimating thenumber of humans present in an area comprising: providing a firsttransceiver disposed at a first location within a detection area;providing a second transceiver disposed at a second location within saiddetection area; a computer server communicably coupled to said firsttransceiver; said first transceiver receiving a first set of wirelesssignals from said second transceiver when no humans are present withinsaid detection area; said computer server receiving a first set ofsignal data from said first transceiver, said first set of signal datacomprising data about properties of said first set of wireless signals;said computer server creating a baseline signal profile for wirelesscommunications from said second transceiver to said first transceiver,said baseline signal profile being based at least in part on saidproperties of said first set of wireless signals in said first set ofsignal data when no humans are present in said detection area; saidfirst transceiver receiving a second set of wireless signals from saidsecond transceiver when a first plurality of humans is present in saiddetection area, said first plurality of humans having a total mass; saidcomputer server receiving a second set of signal data from said firsttransceiver, said second set of signal data comprising data aboutproperties of said second set of wireless signals; said computer servercreating a second baseline signal profile for wireless communicationsfrom said second transceiver to said first transceiver, said secondbaseline signal profile being based at least in part on said propertiesof said second set of wireless signals in said second set of signal datawhen said first plurality of humans is present in said detection area;said first transceiver receiving a third set of wireless signals fromsaid second transceiver when a second plurality of humans is presentwithin said detection area; said computer server receiving a third setof signal data from said first transceiver, said third set of signaldata comprising data about properties of said third set of wirelesssignals; said computer server estimating the total mass of said secondplurality of humans, said estimating based at least in part on acomparison of said properties of said third set of wireless signals insaid third set of wireless signal data to said baseline signal profileand to said baseline signal profile; said computer server estimating thetotal number of humans in said plurality of humans based at least inpart on dividing said estimated total mass of said plurality of humansby an average mass per human.

In a further embodiment, the method comprises: said computer serverestimating the total mass of said second plurality of humans is furtherbased at least in part on a comparison of said properties of said thirdset of wireless signals in said third set of wireless signal data tosaid properties of said second set of wireless signals in said secondset of wireless signal data.

In a further embodiment, the method comprises: said properties of saidfirst set of wireless signals, said second set of wireless signals, andsaid third set of wireless signals comprise wireless network signalprotocol properties determined by said first transceiver.

In a further embodiment, the method comprises: each of said wirelessnetwork signal protocol properties is selected from the group consistingof: received signal strength, latency, and bit error rate.

In a further embodiment, the method comprises: said computer serverestimating comprises interpolating the total mass of humans in saidsecond plurality of humans.

In a further embodiment, the method comprises: said interpolating usesan assumed mass of zero for said baseline signal profile and said totalmass of humans in said first plurality of humans for said secondbaseline signal profile.

In a further embodiment, the method comprises: said total mass is adiscrete user-supplied quantity.

T In a further embodiment, the method comprises: said average mass perhuman is a discrete user-supplied quantity.

In a further embodiment, the method comprises: said computer serverstoring a plurality of historical data records indicative of whether ahuman was present in the detection area over a period of time, each ofsaid historical data records comprising an indication of a number ofhumans detected in said detection area and a date and time when each ofsaid number of humans was detected in said detection area; and saidcomputer server making at least some of said plurality of historicaldata records available to one or more external computer systems via aninterface.

In a further embodiment, the method comprises: said computer serverestimating the total mass of said second plurality of humans is adjustedbased on machine learning comprises: determining a first sample totalmass of a plurality of humans having a fiducial element in saiddetection area, said first sample mass being determined based upondetecting said fiducial element; determining a second sample total massof said plurality of humans in said detection area, said second samplemass being determined based at least in part on a comparison of saidreceived second set of signal data to said baseline signal profile;comparing said first sample mass and said second sample mass; andadjusting said estimation of said total mass of said second plurality ofhumans based upon said comparing.

In a further embodiment, the method comprises: said computer serverestimating the total mass of said second plurality of humans is adjustedbased on machine learning comprises: determining a first sample totalmass of a plurality of humans based on inferences in said detectionarea; determining a second sample total mass of a plurality of humans insaid detection area, said second sample mass being determined based atleast in part on a comparison of said received second set of signal datato said baseline signal profile; comparing said first sample mass andsaid second sample mass; and adjusting said determination of said secondsample mass based upon said comparing.

In a further embodiment, the method comprises: said determining a firstsample location of a human based on inference in said detection areacomprises said computer server inferring from a detected operation of anetwork element in said detection area that a human is present in saiddetection area near said network element.

In a further embodiment, the method comprises: said network component isa component of an electrical system, a lighting system, a heating,venting, and cooling (HVAC) system, a security system, or an industrialautomation system.

In a further embodiment, the method comprises: n said estimating thetotal number of humans in said plurality of humans includes a confidencemetric.

In a further embodiment, the method comprises: said first transceiverand said second transceiver are configured to calculate their relativepositions within said detection area automatically.

In a further embodiment, the method comprises: said wirelesscommunication utilizes a protocol selected from the group consisting of:Bluetooth™, Bluetooth™ Low Energy, ANT, ANT+, WiFi, Zigbee, Thread, andZ-Wave.

In a further embodiment, the method comprises: said wirelesscommunications from said second transceiver to said first transceiverhave a carrier frequency in the range of 850 MHz and 17.5 GHz inclusive.

While the invention has been disclosed in conjunction with a descriptionof certain embodiments, including those that are currently believed tobe preferred embodiments, the detailed description is intended to beillustrative and should not be understood to limit the scope of thepresent disclosure. As would be understood by one of ordinary skill inthe art, embodiments other than those described in detail herein areencompassed by the present invention. Modifications and variations ofthe described embodiments may be made without departing from the spiritand scope of the invention.

The invention claimed is:
 1. A method for estimating the number ofhumans in a space comprising: providing a plurality of transceivers inwireless communication with each other and disposed in a detection area;providing a computer server in communication with each transceiver insaid plurality of transceivers; determining, at said computer server, afirst signal profile for characteristics of wireless communicationsamong said plurality of transceivers when no humans are present in saiddetection area; determining, at said computer server, a second signalprofile for characteristics of wireless communications among saidplurality of transceivers when a first plurality of humans is present insaid detection area, the number of humans in said first plurality beingknown; determining, at said computer server, a third signal profile forcharacteristics of wireless communications among said plurality oftransceivers when a second plurality of humans is present in saiddetection area, the number of humans in said second plurality beingunknown; and using said first signal profile, said second signalprofile, and said known number of humans in said first plurality ofhumans, estimating said unknown number of humans in said secondplurality of humans.
 2. The method of claim 1 where said estimate istime stamped and recorded periodically.
 3. The method of claim 1 wheresaid estimate is provided to a requesting party.
 4. The method of claim3 wherein said requesting party comprises first responders to anemergency at said space.
 5. The method of claim 3 wherein saidrequesting party comprises a robot.
 6. The method of claim 1 whereinsaid signal characteristics are selected from the group consisting of:received signal strength, latency, and bit error rate.
 7. The method ofclaim 1 wherein said estimate is updated by new information from saidplurality of transceivers periodically.
 8. The method of claim 1,further comprising indicating when one of said transceivers is no longertransmitting.
 9. The method of claim 1, further comprising providinginformation received at said computer server from other sensors in saiddetection area and information from one or more sensors disposedexternal said detection area.
 10. The method of claim 1, whereinestimating said unknown number of humans in said said plurality ofhumans comprises comparing signal distortion in said third singleprofile to signal distortion in said first signal profile and signaldistortion in said second signal.